1. Field
The invention relates to optical communication equipment and, more specifically but not exclusively, to adaptive constellations that can be used to encode data at a transmitter and adaptive decision regions that can be used to decode the corresponding noise-impaired optical data signals at a receiver.
2. Description of the Related Art
This section introduces aspects that may help facilitate a better understanding of the invention(s). Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
Transmission of optical communication signals over fiber-optic links is usually impaired by a significant amount of noise, such as additive white Gaussian noise (AWGN) and nonlinear noise. The noise distorts optical communication signals en route from the transmitter to the receiver in a manner that tends to detrimentally affect the bit-error rate (BER), the symbol-error rate (SER), and/or the maximum achievable transmission distance. Therefore, development of modulation/demodulation schemes that can help to mitigate the detrimental effects of optical noise is highly desirable.